scholarly journals Customized Deep Eutectic Solvents as Green Extractants for Ultrasonic-Assisted Enhanced Extraction of Phenolic Antioxidants from Dogbane Leaf-Tea

Foods ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2527
Author(s):  
Ruimin Wang ◽  
Weimin Zhang ◽  
Ruiping He ◽  
Wu Li ◽  
Lu Wang

This study evaluates the application of eco-friendly deep eutectic solvents (DESs) in the extraction of phenolic antioxidants from dogbane leaf-tea (DLT). The results showed DESs with lower viscosity allowed an efficient extraction of significantly higher contents of total phenolics or flavonoids. An innovative and high-efficient solvent, choline chloride-levulinic acid (ChCl-LevA), was screened and used in ultrasonic-assisted extraction (UAE) of phenolic compounds from DLT. According to full factorial design experimental results, total phenolic content (TPC), total flavonoid content (TFC), antioxidant activity, and anti-α-glucosidase activity (α-GIA) of the DLT extracts were simultaneously optimized by response surface methodology. Sonication temperature and water content in ChCl-LevA were found to be the major factors affecting the TPC, TFC, antioxidant activity, and α-GIA of DLT extracts. Under the optimum parameters (water content in ChCl-LevA was 45%, sonication temperature was 50 °C, and extraction time was 30 min), the measured results for all the responses were obtained as follows: TPC-91.38 ± 7.20 mg GAE/g DW, TFC-84.12 ± 3.47 mg RE/g DW, ABTS+-492 ± 7.33 mmol TE/g DW, FRAP-6235 ± 121 μmol Fe(II)/g DW and α-GIA-230 ± 7.59 mmol AE/g DW, which were consistent with the predicted values. In addition, strongly significant positive correlations were observed between TPC/TFC and bio-activities of the DLT extracts. HPLC results indicated high contents of (-)-epigallocatechin (4272 ± 84.86 μg/g DW), catechin (5268 ± 24.53 μg/g DW), isoquercitrin (3500 ± 86.07 μg/g DW), kaempferol 3-O-rutinoside (3717 ± 97.71 μg/g DW), and protocatechuic acid (644 ± 1.65 μg/g DW) were observed in the DLT extracts. In contrast to other extraction methods, ChCl-LevA-based UAE yielded higher TPC, TFC, individual phenolic contents, stronger antioxidant activity, and α-GIA. Scanning electron microscope (SEM) analysis further confirmed that ChCl-LevA-based UAE enhanced the disruption of cell wall structure, thereby making more phenolic antioxidants released from DLT. In short, ChCl-LevA-based UAE was confirmed to be an innovative and high-efficient method for extraction of phenolic antioxidants from DLT. Dogbane leaves can be considered as a good tea source rich in natural antioxidants.

2021 ◽  
Vol 17 ◽  
Author(s):  
Yazid Khaled Khodja ◽  
Mostapha Bachir-Bey ◽  
Rachid Ladjouzi ◽  
Bachra Khettal

Background: The laurel is a shrub native to the Mediterranean basin. It is too often wrongly relegated to the kitchen as a simple condiment while it possesses many therapeutic properties and virtues. The valorization of this plant in terms of bioactive compounds seems to be important. Objective: The aim of the present study is to optimize total phenolic content (TPC) extraction and antioxidant activity from dried bay leaves using conventional process and response surface methodology (RSM). Method: The study of optimization was firstly tested three extraction methods (maceration, ultrasonic-assisted extraction (UAE), and Microwave-assisted extraction (MAE)) then the best one was considered for RSM. Results : The results for the sequential procedure indicated that MAE was the best method for TPC extraction and antioxidant activity of Laurus nobilis leaves. The mathematical modeling of MEA using response surface methodology showed that optimal conditions for phenolic compounds extraction were 57% methanol with microwaves power of 602W during 3.48 minutes. These conditions allowed TPC extraction of 83.53 mg/g and manifested an antioxidant activity of 32.51 mg EAG/g. Conclusion: The validation of models indicated that experimental values were in accordance with predicted ones, demonstrating the suitability of developed models and the success of RSM in the optimization of antioxidants extraction from Laurus nobilis leaves. Therefore, the bay leaves could be considered as an interesting source of phenolic antioxidants.


Antioxidants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 582
Author(s):  
Inês Mansinhos ◽  
Sandra Gonçalves ◽  
Raquel Rodríguez-Solana ◽  
José Luis Ordóñez-Díaz ◽  
José Manuel Moreno-Rojas ◽  
...  

The present study aimed at evaluating the effectiveness of different natural deep eutectic solvents (NADES) on the extraction of phenolic compounds from Lavandula pedunculata subsp. lusitanica (Chaytor) Franco, on the antioxidant activity, and acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and tyrosinase (Tyr) inhibitory capacities. Ten different NADES were used in this research and compared with conventional solvents. Ultrasound-assisted extraction (UAE) for 60 min proved to be the best extraction condition, and proline:lactic acid (1:1) and choline chloride:urea (1:2) extracts showed the highest total phenolic contents (56.00 ± 0.77 mgGAE/gdw) and antioxidant activity [64.35 ± 1.74 mgTE/gdw and 72.13 ± 0.97 mgTE/gdw in 2.2-diphenyl-1-picrylhydrazyl (DPPH) and 2.2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) methods, respectively]. These extracts also exhibited enzymes inhibitory capacity particularly against Tyr and AChE. Even so, organic acid-based NADES showed to be the best extractants producing extracts with considerable ability to inhibit enzymes. Twenty-four phenolic compounds were identified by HPLC-HRMS, being rosmarinic acid, ferulic acid and salvianolic acid B the major compounds. The results confirmed that the combination of UAE and NADES provide an excellent alternative to organic solvents for sustainable and green extraction, and have huge potential for use in industrial applications involving the extraction of bioactive compounds from plants.


Foods ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 140 ◽  
Author(s):  
Pavlović ◽  
Jokić ◽  
Jakovljević ◽  
Blažić ◽  
Molnar

This is the first report on the extraction of cocoa bean shell (CBS) using deep eutectic solvents (DESs). Screening results with 16 different choline chloride-based DESs showed how choline chloride:oxalic acid DES was the most suitable solvent for the extraction of the bioactive compounds from CBS and that concentrations varied greatly depending on the used solvent. The DES extraction was compared to the DESs coupled with microwave extraction (MAE), and the yields of the extracted compounds were higher for DES/MAE. For theobromine, the obtained yields for DES extraction were 2.145–4.682 mg/g, and for caffeine, were 0.681–1.524 mg/g, whereas for DES/MAE, the same compounds were obtained in 2.502–5.004 mg/g and 0.778–1.599 mg/g. Antioxidant activity was also determined, using DPPH method, obtaining 24.027–74.805% activity for DES extraction and 11.751–55.444% for DES/MAE. Water content significantly influenced the extraction of targeted active compounds from CBS, whereas extraction time and temperature did not show statistically significant influence. The extraction temperature only influenced antioxidant activity. The study demonstrated how extraction using DES and microwaves could be of a great importance in the future trends of green chemistry for the production of CBS extracts rich in bioactive compounds.


Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1781
Author(s):  
Sofia Chanioti ◽  
Maria Katsouli ◽  
Constantina Tzia

Olive pomace, the solid by-product derived from olive oil production consists of a high concentration of bioactive compounds with antioxidant activity, such as phenolic compounds, and their recovery by applying innovative techniques is a great opportunity and challenge for the olive oil industry. This study aimed to point out a new approach for the integrated valorization of olive pomace by extracting the phenolic compounds and protecting them by encapsulation or incorporation in nanoemulsions. Innovative assisted extraction methods were evaluated such as microwave (MAE), homogenization (HAE), ultrasound (UAE), and high hydrostatic pressure (HHPAE) using various solvent systems including ethanol, methanol, and natural deep eutectic solvents (NADESs). The best extraction efficiency of phenolic compounds was achieved by using NADES as extraction solvent and in particular the mixture choline chloride-caffeic acid (CCA) and choline chloride-lactic acid (CLA); by HAE at 60 °C/12,000 rpm and UAE at 60 °C, the total phenolic content (TPC) of extracts was 34.08 mg gallic acid (GA)/g dw and 20.14 mg GA/g dw for CCA, and by MAE at 60 °C and HHPAE at 600 MPa/10 min, the TPC was 29.57 mg GA/g dw and 25.96 mg GA/g dw for CLA. HAE proved to be the best method for the extraction of phenolic compounds from olive pomace. Microencapsulation and nanoemulsion formulations were also reviewed for the protection of the phenolic compounds extracted from olive pomace. Both encapsulation techniques exhibited satisfactory results in terms of encapsulation stability. Thus, they can be proposed as an excellent technique to incorporate phenolic compounds into food products in order to enhance both their antioxidative stability and nutritional value.


Author(s):  
ROSITA HANDAYANI ◽  
ANDRE BANGUN ◽  
PASKAH DEWI DEBORAH ◽  
ABDUL MUN’IM

Objective: This work aimed to determine the optimal extraction conditions of Mahkota dewa using different extraction methods: microwave-assistedextraction with ethanol (MAE-ethanol), ultrasonic-assisted extraction using a choline chloride natural deep eutectic solvent (UAE-NADES), andSoxhlet and reflux extractions.Methods: Experimental design was performed through Box-Behnken. The efficiency of the methods was evaluated based on the total phenolic content(TPC) and antioxidant activity. The presence of relevant compounds was qualitatively assessed by high-performance liquid chromatography (HPLC).Results: For the MAE-ethanol method, optimum extraction was achieved with 65% ethanol, in 1 min under 30% microwave power, and a 1:12 sample–solvent ratio, which yielded a TPC and antioxidant activity of 62.79±0.74 mg gallic acid equivalents (GAE)/g powder and 30.48±0.32%, respectively. InUAE-NADES, the optimal conditions were choline chloride: lactic acid ratio of 1:4 with a 50% water addition, 20 min extraction (TPC and antioxidantactivity of 65.25 mg GAE/g powder and 26.45±0.02%). The Soxhlet and reflux methods gave a TPC of 49.68±0.59 and 50.98±0.54 mg GAE/g powder,and antioxidant activity of 22.87±0.13% and 25.97±0.34%, respectively. Qualitative HPLC analysis showed the presence of quercetin, mahkoside A,4,6-dihydroxy-4-methoxybenzophenone-2-O-β-D-glucopyranoside, and mangiferin.Conclusion: MAE-ethanol was more efficient than the conventional Soxhlet and reflux methods and performed similarly to UAE-NADES in terms of TPC.


2020 ◽  
Vol 10 (14) ◽  
pp. 4830
Author(s):  
Nevena Dabetić ◽  
Vanja Todorović ◽  
Manuela Panić ◽  
Ivana Radojčić Redovniković ◽  
Sladjana Šobajić

In the past few years, research efforts have focused on plant exploitation for deriving some valuable compounds. Extraction has been usually performed using petrochemical and volatile organic solvents, but nowadays, increased recognition of environmental pollution has prompted the utilization of green solvents as alternatives. Therefore, the aim of the present study was to exploit deep eutectic solvents (DES) (choline chloride: citric acid and choline chloride: glucose) as solvents for extracting valuable phenolic antioxidants from grapes. Investigation was conducted on ten grape varieties, observing seeds and skin as different matrix. Total polyphenol content (TPC) was determined by Folin-Ciocalteu spectrophotometric microassay. Antioxidant activity was investigated using four different tests and results were combined in a unique Antioxidant Composite Index (ACI) to reveal comprehensive information about this biological activity. Polyphenol compounds were identified and quantified with the aim of HPLC-diode array detector (DAD). Overall results support that DES (particularly choline chloride: citric acid) were comparable to conventional solvent, and in most cases even outperformed acidified aqueous ethanol (concerning extraction efficiency and antioxidant activity). Regardless of varietal distinctions, grape seeds have higher antioxidant capacity compared to grape skin, and such findings are according to their phenol compound concentrations.


2017 ◽  
Vol 03 ◽  
pp. 7
Author(s):  
Asma Nisar ◽  
Awang Soh Mamat ◽  
Md Irfan Hatim ◽  
Muhammad Shahzad Aslam ◽  
Muhammad Syarhabil Ahmad ◽  
...  

Deep eutectic solvents as a new type of eco-friendly solvents have attracted attention in chemistry, medicine, and other fields for the extraction and separation of target compounds from medicinal plants. Deep eutectic solvents are easy to prepare and have many advantages as solvents, such as chemical inertness with water, low cost, easy biodegradability, and pharmaceutically acceptable toxicity. In this study, a deep eutectic solvent made up of choline chloride-glycerol (1:2) was used for the extraction of flavonoids from Catharanthus roseus plant parts (flower petal, leaves, stem, and root). The highest amount of phenolic content was detected in flower petal, that is, 194.50 mg GAE/g. In DPPH test, the maximum amount of antioxidant activity determined in the flower petal was 73.13%; IC50 was calculated by using a linear regression equation; IC50 value of the standard, stem, root, leaf, and flower petal was 13.22, 90.44, 83.93, 120.14, 79.49 μg/ml, respectively. The result of this research is that Catharanthus roseus has a compatible antioxidant activity. This can be helpful for the treatment of diseases caused by free-radical oxidative stress.


Author(s):  
Abderrezak Kennas ◽  
Hayat Amellal-Chibane

Background: Pomegranate peels are rich in bioactive compounds and could be an alternative natural source such as antioxidants. Aims: The aim of the present study was to assess the abilities of five solvents to extract phenolic antioxidants from pomegranate peels. Methods and Material: Pomegranate peels powder was subjected to extraction and the extraction yield was compared. The total phenolic, flavonoid, condensed and hydrolysable tannins contents were analyzed. The antioxidant activity of the extracts was evaluated by two methods (DPPH* and ABTS•+ scavenging capacities) and results were then compared. Results: Results showed that the mixture methanol/water (50:50) allowed higher extraction yield (37.33±5.3%) than the others solvents (P<0.05). Further, the total phenolic, flavonoid and condensed tannins contents were the highest in mixture water/methanol (50:50) extract. Phenolic antioxidants showed a distinct reducing capacity and a high DPPH* inhibition values were recorded for all extracts with no significant differences (P>0.05) between ethanol and mixture water/methanol (50:50) extracts. All extracts exhibited high inhibition against ABTS•+ but with a considerable variation. Phenolic content and antioxidant activities were well positively correlated with each other. Conclusions: Our findings revealed that the choice of the extracting solvent affects considerably the extraction of phenolic antioxidants from pomegranate peels. Keywords: Pomegranate peels, solvent extraction, antioxidant activity, phenolic antioxidants.


2014 ◽  
Vol 68 (5) ◽  
Author(s):  
Hafizah Mohd Hadzri ◽  
Mohd Azizi Che Yunus ◽  
Salman Zhari ◽  
Fahim Rithwan

The effects of different types of solvents and extraction method were investigated to determine the presence of antioxidant contents and activity from the P. niruri plant. The aim of this study is to determine which extraction method will give higher natural antioxidant contents and antioxidant activity. The content of natural antioxidant and antioxidant activity were analysed by total phenolic content (TPC), total flavonoid content (TFC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity assay. The results showed that extracts from a supercritical fluid extraction (SFE) method without the addition of modifier showed the highest content of total phenolic (187.66 mg GAE/ g) and flavonoid (1100.93 mg QE/g) in P. niruri compared to the other methods of extraction with different type of solvents. The extract of P. niruri from different extraction methods showed antioxidant activity on DPPH radical scavenging assay. The soxhlet extraction method by methanol showed the lowest IC50 compared to the other methods of extraction. The results revealed that P. niruri extracts had different content of antioxidant and antioxidant activity. The solvent polarity and different methods of extraction play significant roles in determining the most suitable method for production of antioxidant contents and antioxidant activity from P. niruri extracts.


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